Poster - Thurs Eve-25: Depth dependence of electron backscatter for electron radiotherapy: A Monte Carlo study

Medical Physics
James C L Chow, Amir M Owrangi

Abstract

The aim of this study is to investigate the depth dependence of electron backscatter from lead (Pb) for clinical electron beams using Monte Carlo simulations. Phase-space files for the 4 and 9MeV electron beams based on the Varian 21EX Linac were generated using the BEAMnrc code. A 3mm Pb layer was irradiated by the phase-space beams with 0.5 and 1cm depth of water on top. Electron energy spectra at different depths in water with and without the Pb layer were determined using the BEAMnrc code. For energy spectra of the 4 MeV beams with 0.5cm depth of water, electron backscatter was found at both the Pb-water interface and 0.5cm of water over the Pb. However, electron backscatter almost disappeared at 0.5 and 1cm of water over the Pb, when 1cm depth of water was used. This is because the increased attenuations of the (1) 4MeV beam from the thicker water layer, and (2) electron backscatter in water above the Pb. For the 9MeV beams with 0.5cm depth of water, only slight electron backscatter was observed. More electron backscatter was found when 1cm depth of water was used. It is because the electron beam energy was reduced more due to the attenuation of the 1 cm depth of water compared to 0.5 cm. Since the electron energy spectrum...Continue Reading

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.